1. Field of Invention
The present invention relates to an intake system mounted to a vehicle, and more particularly, to a variable intake system which optimally controls an angle of a variable intake valve according to an RPM of an engine, an intake pressure, and an opening angle of a variable flap to optimize performance in various operation regions, and an apparatus and a method for controlling the same.
2. Description of Related Art
A variable intake system mounted to a vehicle opens and closes an auxiliary duct according to a load of an engine to improve noise performance without causing loss of intake pressure.
A variable intake system mounted to a vehicle according to the related art has a structure where an intake duct branched to two parts is connected to an air cleaner housing, and opens one part of the intake duct if an engine is in a low speed region and opens both the two parts of the intake duct if the engine is in a high speed region.
The variable intake system includes a valve assembly for selectively opening and closing one of the two intake ducts and an actuator for supplying a driving force to the valve assembly.
The actuator may be classified into a semi-active type and an active type.
The semi-active actuator includes, for example, a vacuum type actuator using a solenoid and a naturally opened/closed actuator using a magnet, and the active actuator employs a DC motor.
However, the semi-active actuator according to the related art cannot easily adjust an opening area of an intake duct, cannot be fully opened at a maximum RPM of an engine, causing a loss of maximum output due to an increase of intake pressure, may degrade the linearity in acceleration booming, and may retard response speed, which is undesirable.
Further, while the active actuator according to the related art can be variably opened according to a mode thereof and can achieve quick response, it increases manufacturing costs, makes a power transmitting part complex, generates noise at a choking part and the like, and makes a prompt and accurate control difficult as it employs an high-priced DC motor as compared with a semi-active actuator, which is also undesirable.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.